JarCastingjshell-scripting-weka-package
Weka package offering scripting via jshell from the GUI chooser, using the jshell-scripting library.
Under the hood, the jshell executable is started with a custom classpath compiled from the current JVM, executing the current content of the editor saved as a temporary script file.
The package requires you to start Weka with Java 9 or later.
Examples
J48
The following code loads the UCI dataset anneal, cross-validates J48 on it and outputs the summary statistics.
import weka.core.Instances;
import weka.core.converters.ConverterUtils.DataSource;
import weka.classifiers.trees.J48;
import weka.classifiers.Evaluation;
import java.util.Random;
Instances data = DataSource.read("/some/where/anneal.arff");
data.setClassIndex(data.numAttributes() - 1);
J48 cls = new J48();
Evaluation eval = new Evaluation(data);
eval.crossValidateModel(cls, data, 10, new Random(1));
System.out.println(eval.toSummaryString());
M5P
In this case, M5P is cross-validated on the UCI dataset bolts:
import weka.core.Instances;
import weka.core.converters.ConverterUtils.DataSource;
import weka.classifiers.trees.M5P;
import weka.classifiers.Evaluation;
import java.util.Random;
Instances data = DataSource.read("/some/where/bolts.arff");
data.setClassIndex(data.numAttributes() - 1);
M5P cls = new M5P();
Evaluation eval = new Evaluation(data);
eval.crossValidateModel(cls, data, 10, new Random(1));
System.out.println(eval.toSummaryString());
LibSVM (package)
Since jshell is a separate process with its own classpath, classes within packages are not visible directly. For getting access to packages, you need to load all Weka packages using WekaPackageManager.loadPackages(false, false, false) and then instantiate classes via the Utils.forName method. Setting options is possible via the setOptions method.
In the following example, the LibSVM classifier (from the LibSVM package) is instantiated and then cross-validated on the UCI dataset anneal:
import weka.core.Instances;
import weka.core.converters.ConverterUtils.DataSource;
import weka.core.OptionHandler;
import weka.core.Utils;
import weka.core.WekaPackageManager;
import weka.classifiers.Evaluation;
import weka.classifiers.Classifier;
import java.util.Random;
WekaPackageManager.loadPackages(false, false, false);
Instances data = DataSource.read("/some/where/anneal.arff");
data.setClassIndex(data.numAttributes() - 1);
Classifier cls = (Classifier) Utils.forName(Classifier.class, "weka.classifiers.functions.LibSVM", new String[0]);
((OptionHandler) cls).setOptions(new String[]{"-K", "2"});
Evaluation eval = new Evaluation(data);
eval.crossValidateModel(cls, data, 10, new Random(1));
System.out.println(eval.toSummaryString());
Releases
Click on one of the following links to download the corresponding Weka package:
Maven
Add the following dependency in your pom.xml to include the package:
<dependency>
<groupId>com.github.fracpete</groupId>
<artifactId>jshell-scripting-weka-package</artifactId>
<version>2019.4.3</version>
<type>jar</type>
<exclusions>
<exclusion>
<groupId>nz.ac.waikato.cms.weka</groupId>
<artifactId>weka-dev</artifactId>
</exclusion>
</exclusions>
</dependency>